The current study sought to identify morphological traits that may be used as direct or indirect selection criterion to improving water-use efficiency and drought tolerance in wheat. Several traits such as number of leaves, number of tillers, plant height and dry mass were significantly correlated with photosynthetic rate and instantaneous water use-efficiency in the current study. These suggest that such traits could be used as indirect selection criterion for breeding wheat for high water-use efficiency and photosynthetic capacity. Further, traits such as number of tillers and dry matter exhibited high values for heritability and genetic advance values indicating genetic gains incorporating this trait to improve WUE in wheat is possible. Number of tillers and dry matter were also significantly and positively correlated with grain yield under water stress conditions suggesting the possible effectiveness in increasing grain yield under water stress condition. Overall, genotypes G339, G343 and G344 which exhibited high NT and DM under WS condition were selected with enhanced water- use efficiency for breeding and to boost wheat production under dryland environments.
125 References
Abayomi Y.A., Wrght D. (1999) Effects of water stress on growth and yield of spring wheat (Triticum aestivum L.) cultivars. Tropical Agriculture 76:120-125.
Abdoli M., Saeidi M., Jalali-Honarmand S., Mansourifar S., Ghobadi M., Cheghamirza K. (2013) Effect of source and sink limitation on yield and some agronomic characteristics in modern bread wheat cultivars under post anthesis water deficiency. Acta Agriculturae Slovenica 101:173 -182
Abdolshahi R., Nazari M., Safarian A., Sadathossini T.S., Salarpour M., Amiri H.
(2015) Intergrated selection criteria for drought tolerance in wheat (Triticum aestivum L.) breeding programs using discriminant analysis. Field Crops Research 174:20-29.
Amanullah J., Hassan M.J., Nawab K., Ali A. (2007) Response of specific leaf area (SLA), leaf area index (LAI) and leaf area ratio (LAR) of maize (i L.) to plant density, rate and timing of nitrogen application. World Applied Science Journal 2:235-43.
Akram M. (2011) Growth and yield components of wheat under water stress of different growth stages. Bangladesh Journal of Agriculture Research 36:455- 468.
Allahverdiyev T., Huseynova I. (2017) Influence of water deficit on photosynthetic activity, dry Matter partitioning and grain yield of different durum and bread wheat genotypes. Cereal Research Communications 45:432–441.
Aminzadeh G. (2010) Evaluation of seed yield stability of wheat advanced genotypes in Ardabil, Iran. Research Journal of Environmental Sciences 4:478-482.
Anjum S.A., Xie X.-U., Wang L.C., Saleem M.F., Man C., Lei W. (2011) Morphological, physiological and biochemical responses of plants to drought stress. African Journal of Agricultural Research 6:2026-2032.
Anyia A., Herzog H. (2004) Water-use efficiency, leaf area and leaf gas exchange of cowpea under mid-season drought. European Journal of Agronomy 20:327- 339.
Araus J.L., Slafer G.A., Royo C., Serret M.D. (2008) Breeding for yield potential and stress adaptation in cereals. Plant Science 27:377-412.
Bartels D., Sunkar R. (2005) Drought and salt tolerance in plants. Critical Reviews in Plant Sciences 24:23-58.
Blum A. (1996) Crop responses to drought and the interpretation of adaptation. Plant Growth and Regulation 120:135-148.
Blum A. (2005) Drought resistance, water-use efficiency, and yield potential are they compatible, dissonant, or mutually exclusive? Australian Journal of Agricultural Research 56: 1159-1168.
Chen W., Deng X.-P., Eneji A.E., Wang L.L., Xu Y., Cheng Y. (2014) Dry-matter partitioning across parts of the wheat internode during the grain filling period as influenced by fertilizer and tillage treatments. Communications in Soil Science and Plant Analysis 45:1799-1812.
Chen X., Min D., Yasir T.A., Hu Y.G. (2012) Evaluation of 14 morphological, yield- related and physiological traits as indicators of drought tolerance in Chinese winter bread wheat revealed by analysis of the membership function value of drought tolerance (MFVD). Field Crops Research 137:195-201.
Condon A.G., Richards R.A., Rebetzke J.G., Farquhar D.G. (2004) Breeding for high water use efficiency. Journal of Experimental Botany 55:2447–2460.
Crossa J., Gauch H.G., Zobel R.W. (1990) Additive main effects and multipicative interction analysisof two international maize cutivar trials. Crop Science 30:493- 500.
Ehleringer J.R., Hall A.E., Farguhar G.D. (1993) Introduction: water use in relation to productivity. In: Ehleringer JR, Hall AE, Farguhar G.D, Eds. Stable isotopes and plant carbon water relations. San Diego. Academic Press: 555:3–8.
Erice G., Irigoyen J.J., Sanchez-Dıaz M., Avice J.J., Ourry A. (2007) Effect of drought, elevated CO2 and temperature on accumulation of N and vegetative storage proteins (VSP) in taproot of nodulated alfalfa before and after cutting. Plant Science. 172:903-912.
127
Falconer D.S. (1989) Introduction to quantitative genetics. Longman Science and Technology., London And New York.
Falconer D.S., Mackay T.F.C. (1996) Introduction to Quantitative genetics.4th edition.
Longmans Green, Harlow, Essex, UK.
Farooq M., Wahid A., Kobayashi N., Fujita D., Basra S.M.A. (2009) Plant drought stress: effects, mechanisms and management. Agronomy for Sustainable Development 29:185-212. .
Farshadfar E., Poursiahbidi M.M., Safavi S.M. (2013) Assessment of drought tolerance in land race of bread wheat based on resistance/tolerance indices.
International Journal of Advances in Biological and Biomedical Research.
1:143-158.
Fleury D., Jefferies S., Kuchel H., Langridge P. (2010) Genetic and genomic tools to improve drought tolerance in wheat. Journal of Experimental Botany 61:3211- 3222.
Flexas J., Niinemets U., Gallé A., Barbour M.M., Centritto M., Diaz-Espejo A., Douthe C., Galmés J., Ribas-Carbo M., Rodriguez P.L. (2013) Diffusional conductances to CO2 as a target for increasing photosynthesis and photosynthetic water-use efficiency. Photosynthesis Research 117:45-59.
Flexas J., Díaz-Espejo A., Conesa M.A., Coopman R.E., Douthe C., Gago J., Gallé A., Galmés J., Medrano H., Ribas-Carbo M. (2016) Mesophyll conductance to CO2 and Rubisco as targets for improving intrinsic water use efficiency in C3
plants. Plant Cell Environment 39:965-982.
Garcial del Moral L.F., Rharrabti Y., Villegas D., Royomm C. (2003) Evaluation of grain yield and its components in Durum Wheat under Mediterranean conditions: An Ontogenic Approach. Agronomy Journal. 95:388-396.
Gupta N.K., Gupta S., Kumar A. (2001) Effect of water stress on physiological attributes and their relationship with growth and yield in wheat cultivars at different growth stages. Journal of Agronomy 86:1437-1439.
Guttieri M.J., Stark J.C., Obrien K., Souza E. (2001) Relative sensitivity of spring wheat grain yield and quality parameters to moisture deficit. Crop Science 41:327- 335.
He Z., Rajaram S. (1994) Differential responses of bread wheat characters to high temperature. Euphytica 72:197–203.
Johnson H.W., Robinson H.F., Comstock R.E. (1955) Estimates of genetic and environmental variability in soybeans. Agronomy Journal 47:314-318.
Khokhar M., Hussain M., Anwar J., Zulkiffal M., Muzaffar Iqbal M., Baz Khan S., Arif Khan M., Qayyum A., Sabir W., Mehmood S. (2018) Correlation and path analysis for yield and yield contributing characters in wheat (Triticum aestivum L.).
Liu H., Meuwissen T., Sorensen A., Berg P. (2015) Upweighing rare favourable alleles increases long-term genetic gain in genomic selection programs genetic selection evolution. Genetics Selection Evolution 47:19-32.
Maniee M., Kahrizi D., Mohammadi R. (2009 ) Genetic variability of some morpho- physiological traits in durum wheat (Triticum turgidum var. durum). Journal of Applied Science 9:1383–1387.
Mbave Z.A. (2013) Water stress effects on growth, yield and quality of wheat (Triticum aestivum L.). MSc dissertation. University of Pretoria.
Merchuk-Ovnat, L., Fahima, T., Krugman, T., Saranga, Y. (2018) Ancestral QTL alleles from wild emmer wheat improve grain yield, biomass and photosynthesis across environments in modern wheat. Plant Science 251:23–34
Messina C.D., Sinclair T.R., Hammer G.L., Curan D., Thompson J., Oler Z., Gho C., Cooper M. (2015) Limited-transpiration trait may increase maize drought tolerancein the us corn belt. Agronomy Journal 107:1978-1986.
Munns R., James R.A., Sirault X.R.R., Furbank R.T., Jones H.G. (2010) New phenotyping methods for screening wheat and barley for beneficial responses to water deficit. Journal of Experimental Botany 61:3499-3507.
129
Mwadzingeni L., Shimelis, H, Tsilo, T.J. (2017) Variance components and heritability of yield and yield components of wheat under drought stressed and non- stressed conditions. Australian Journal of Crop Science 11: 1425-1430.
Mwadzingeni, L., Shimelis, H, Tesfay, S, Tsilo, T.J. (2016) Screening of bread wheat genotypes for drought tolerance using phenotypic and proline analyses.
Frontiers in Plant Science 7:1-12.
Nagai T., Makino A. (2009) Differences between rice and wheat in temperature responses of photosynthesis and plant growth. Plant and Cell physiology 50:744-755.
Nouri-Ganbalani A., Nouri-Ganbalani G., Hassanpanah D. (2009) Effects of drought stress condition on the yield and yield components of advanced wheat genotypes in Ardabil, Iran. Journal of Food, Agriculture and Environment 7:228–234.
Pirdashti H., Sarvestani Z.T., Nematzadch G., Ismail A. (2004.) Study of water stress effects in different growth stages on yield and yield components of different rice (Oryza sativa L.) cultivars: 4th International Crop Science Congress 1-7.
Pommel B., Gallais A., Coque M., Quillere I., Hirel B., Prioul J.L., Andrieu B., Floriet M. (2006) carbon and nitrogen allocation and grain filling in three maize hybrids differing in leaf senescence. European Journal of Agronomy 24:203-211.
Rana J.C., Sharma T.R., Tyagi R.K., Chahota R.K., Gautam N.K., Sharma Mohar Singh P.N., Ojha S.N. (2015) Characterisation of 4274 accessions of common bean (Phaseolus vulgaris L.) germplasm conserved in the Indian gene bank for phenological, morphological and agricultural traits. Euphytica 205: 441-457.
Reynolds M., Tuberosa R. (2008) Translational research impacting on crop productivity in drought-prone environments. Current Opinion in Plant Biology 11:171-179.
Robinson H.F., Comstock R.E., Harvey P.H. (1949) Estimates of heretibility and the degree of dominance in corn. Agronomy Journal 41:353-359.
Ryan A.C., Dodd I.C., Rothwell S.A., Jones R., Tardieu F., Draye X., Davies W.J.
(2016) Gravimetric phenotyping of whole plant transpiration responses to
atmospheric vapour pressure deficit identifies genotypic variation in water use efficiency. Plant Science 251:101-109.
Sayar R., Khemira H., Bensalem M., Kameli A. (2005) Drought tolearance eveluation test for durum wheat (Triticum durum Desf.), poster in International Conference on Intergrate Approches to sustain and improve plant production under drought stress. International Drought-II:3-61.
Schuppler U., He P.-H., John P.C.L., Munns R. (1998) Effect of water stress on cell division and Cdc2-Like cell cycle kinase activity in wheat leaves. Plant Physiology 117:667-678.
Simane B., Struik P.C., Rabbinge R. (1998) Growth and yield component analysis of durum wheat as an index of selection to terminal moisture stress. Tropical Agriculture 75:363-368.
Sinclair T.R., Hammer G.L., Van Oosterom E.J. (2005) Potential yield and water-use efficiency benefits in sorghum from limited maximum transpiration rate.
Functional Plant Biology 32:945-952.
Sinclair T.R., Devi J., Shekoofa A., Choudhary S., Sadok W., Vadez V., Riar M., Rufty T. (2017) Limited-transpiration response to high vapor pressure deficit in crop species. Plant Science 260:109-118.
Singh R.K., Chaudhary B.D. (1977) Biometrical methods in quantitative genetic analysis. Kalnani publishers, New Delhi, India: 39-68
Solomon K.F., Labuschagne M.T. (2009) Morpho-physiological response of durum wheat genotypes to drought stress. South African Journal of Plant and Soil 26:141-146.
Sharma P., Jha, A. B., Dubey, R. S., and Pessarakli, M. (2012). Reactive oxygen species, oxidative damage, and antioxidative defense mechanism in plants under stressful conditions. Journal of Botany.2012:1-26.
Tambussi E.A., Bort J., Araus J.L. (2007) Water use efficiency in C4 cereal under Mediterranean conditions: a review of some physiological aspects. Annals of Applied Botany 150:307-321.
131
Théroux R.G., Éthier G., Pepin S. (2015) Greater efficiency of water use in poplar clones having a delayed response of mesophyll conductance to drought. Tree Physiology 35:172-184.
Tomm G.O., Didonet A.D., Sandri J.L., Frizon M.I. (2000) Lodging in Wheat:
Relationships with Soil Fertility and Plant Characteristics in Southern Brazil.
Wheat in a Global Environment Developments in Plant Breeding. Springer, Dordrecht 9:647-653.
Tshikunde N.M., Odindo A., Shimelis H., Mashilo J. (2018) leaf gas exchange and water-use efficiency of dry-land wheat genotypes under water stressed and non-stressed conditions. ACTA Agriculturae Scandinavica, Section B- Soil and Plant Science 68:738-748.
Varga B., Vida G., Varga‐László E., Bencze S., Veisz O. (2015) Effect of simulating drought in various phenophases on the water use efficiency of winter wheat.
Journal of Agronomy and Crop Science 201:1-9.
Villagra P.E., Cavagnaro J.B. (2006) Water stress effects on the seedling growth of Prosopis argentina and Prosopis alpataco. Journal of Arid Environment 64:390- 400.
Vurayai R., Emongor V., Moseki B. (2011) Effect of water stress imposed at different growth and development stages on morphological traits and yield of Bambara groundnuts (Vigna subterranea L. Verdc). American Journal of Plant Physiology 6:17-27.
Yin C.Y., Wang X., Duan B.L., Luo J.X., Li C.Y. (2005) Early growth,dry matter allocation and water use efficiency of two sympatric Populus species as affected by water stress. Environmental & Experimental Botany 53:315-322.
Zhu X.G., Long S.P., Ort D.R. (2010) Improving photosynthetic efficiency for greateryield. Annual Review of Plant Biology 61:235–261.
An overview of the research findings Introduction and objectives of the study
Global wheat production and productivity is hindered by drought stress, especially under rain-fed production conditions (Li et al., 2009). There is need to improve drought tolerance and water-use efficiency of wheat to boost production (Medrano et al., 2015).
The aim of this study was to evaluate and select drought tolerant wheat genotypes possessing key yield-influencing and drought-adaptive agronomic and physiological traits for high-yield potential, enhanced drought tolerance and water-use efficiency for breeding or direct production under water-limited regions in South Africa
This overview compares the original study objectives with the research findings in relation with each objective. In addition, the implications of the study are provided for drought tolerance breeding and water use efficiency in wheat.
Objectives of the study
1. To determine drought tolerance of dryland wheat genotypes based on leaf gas exchange and water-use efficiency in order to identify promising genotypes for drought tolerance breeding.
2. To examine associations between morphological and physiological traits of selected wheat genotypes under drought stress in order to identify unique traits that may be used as direct or indirect selection criterion for improving water- use efficiency and drought tolerance in wheat.
Research findings in brief:
Leaf gas exchange and water-use efficiency of dry-land wheat genotypes under water stress and non-stressed conditions
In this study the physiological responses of ten genetically diverse wheat genotypes were studied under non-stressed (NS) and water stressed (WS) conditions using a 2
× 10 factorial experiment replicated 3 times. The core findings of the study were:
Significant genetic variation was observed amongst the tested wheat genotypes using various physiological parameters.
133
Genotypes G339 and G344 were identified as drought tolerant with high values of photosynthetic rate, transpiration rate, stomatal conductance, the ratio of photosynthetic rate and internal CO2 concentration (A/Ci), intrinsic water use efficiency (WUEi) and instantaneous water-use efficiency (WUEinst). These are useful for breeding for enhanced drought tolerance and water-use efficiency to improve grain yield potential under drought stress environments.
Morpho-physiological traits associated with water-use efficiency in selected dry land wheat (Triticum aestivum L.) genotypes
Ten selected and genetically diverse wheat genotypes were assessed under non- stressed (NS) and water-stressed (WS) conditions using a randomised complete block design with three replications. The main findings of the study were:
Genotypes G339, G343 and G344 produced higher number of tillers and dry biomass and recorded high heritability and genetic advances for number of tillers and dry biomass under water stress condition
There were positive and significant correlations between number of tillers, dry biomass and grain yield under water stress condition suggesting selection for these traits will likely increase yield gains in wheat.
Genotypes G339, G343 and G344 showed high number of tillers and biomass production under WS were identified and selected for breeding for enhanced water-use efficiency to boost wheat production under dryland environments.
Implications of the research findings
The following major implications for breeding were noted:
The identified drought tolerance wheat genotypes can be used as parental lines to develop breeding populations to improve grain yield and drought tolerance under water limited conditions.
Some genotypes can be used for direct cultivation following genotype-by- environment analysis to identify stable genotypes